During radial-axial ring rolling process, cooperative strategy of the radial axial feed is critical for dimensional accuracy and thermo mechanical parameters distribution of the formed ring. In order to improve the co...During radial-axial ring rolling process, cooperative strategy of the radial axial feed is critical for dimensional accuracy and thermo mechanical parameters distribution of the formed ring. In order to improve the comprehensive quality of the ring parts, response surface method （RSM） is employed for the first time to optimize the cooperative feed strategy for radial-axial ring rolling process by combining it with an improved and verified 3D coupled thermo-mechanical finite element model. The feed trajectory is put forward to describe cooperative relationship of the radial- axial feed and three variables are designed based on the feed trajectory. In order to achieve multi- objective optimization, four responses including thermo mechanical parameters distribution and rolling force are proposed. Based on the FEM results, RSM is used to establish a response model to depict the function relationship between the objective response and design variables. Through this approximate model, effects of different variables on ring rolling process are analyzed connect- edly and optimal feed strategy is obtained by resorting to the optimal chart specific to a constraint condition.展开更多
如何根据电网的拓扑结构和实时负荷合理地确定柔性交流输电系统(flexible AC transmission systems,FACTS)装置的配置成为近年研究热点。为了能够在计算无功补偿的过程中考虑影响配置的多种因素,提出了多目标无功优化的计算方法。通过...如何根据电网的拓扑结构和实时负荷合理地确定柔性交流输电系统(flexible AC transmission systems,FACTS)装置的配置成为近年研究热点。为了能够在计算无功补偿的过程中考虑影响配置的多种因素,提出了多目标无功优化的计算方法。通过遗传算法,以有功功率损耗和投资这两个目标函数建立多目标数学寻优模型,并设定节点电压偏差评价函数为约束破坏函数。分析由前沿曲线得出的折中解可知:经过补偿后网络的有功功率损耗下降超过5%;而且采用遗传算法多目标进行无功配置后不仅能够有效地降低网络的有功功率损耗,还为决策者提供了多种配置选择,使得决策者可以根据实际需要选择恰当合适的补偿配置。在与经济压差法确定无功补偿容量的对比中,多目标优化方法虽然在降低有功功率损耗方面与经济压差法相差无几,但是设备投资则大为节省。展开更多
基金Specialized Research Fund for the Doctoral Program of Higher Education(No.20126102120022) of ChinaNorthwestern Polytechnical University(NPU) Foundation for Fundamental Research(NPU-FFR-JC200822) of China for the support given to the research
文摘During radial-axial ring rolling process, cooperative strategy of the radial axial feed is critical for dimensional accuracy and thermo mechanical parameters distribution of the formed ring. In order to improve the comprehensive quality of the ring parts, response surface method （RSM） is employed for the first time to optimize the cooperative feed strategy for radial-axial ring rolling process by combining it with an improved and verified 3D coupled thermo-mechanical finite element model. The feed trajectory is put forward to describe cooperative relationship of the radial- axial feed and three variables are designed based on the feed trajectory. In order to achieve multi- objective optimization, four responses including thermo mechanical parameters distribution and rolling force are proposed. Based on the FEM results, RSM is used to establish a response model to depict the function relationship between the objective response and design variables. Through this approximate model, effects of different variables on ring rolling process are analyzed connect- edly and optimal feed strategy is obtained by resorting to the optimal chart specific to a constraint condition.
文摘如何根据电网的拓扑结构和实时负荷合理地确定柔性交流输电系统(flexible AC transmission systems,FACTS)装置的配置成为近年研究热点。为了能够在计算无功补偿的过程中考虑影响配置的多种因素,提出了多目标无功优化的计算方法。通过遗传算法,以有功功率损耗和投资这两个目标函数建立多目标数学寻优模型,并设定节点电压偏差评价函数为约束破坏函数。分析由前沿曲线得出的折中解可知:经过补偿后网络的有功功率损耗下降超过5%;而且采用遗传算法多目标进行无功配置后不仅能够有效地降低网络的有功功率损耗,还为决策者提供了多种配置选择,使得决策者可以根据实际需要选择恰当合适的补偿配置。在与经济压差法确定无功补偿容量的对比中,多目标优化方法虽然在降低有功功率损耗方面与经济压差法相差无几,但是设备投资则大为节省。
